Tapping or drilling machine power transmission



TAPPING 0R DRILLING MACHINE POWER TRANSMISSION Filed Feb. 19, 1962 A. F.HEIMERL 2 Sheets-Shegt 1 ATTORNEY Aug. 27, 1963 A. F. HEIMERL 3,101,630

TAPPING OR DRILLING MACHINE POWER TRANSMISSION Filed Feb. 19, 1962 2Sheets-Sheet 2 '-.IilIL i 57 l MLRH [s INVENTOR. ANTHONY 'f HE/Meez.

ATTotzNev United States Pavtent This invention relates to va machinetool for advancing a rotating cutting tool'into a work, and is moreparticularly directed to a drilling or tapping machine.

'In operating machine ftools of the above class, wherein vthe advance ofthe tool and the axial load is dependent on the operator, diicultyarises. Thus, as the cutting tool dulls and the-operator exerts anexcessive axial force, the cutting tool may break. Additionally, shouldthe chips accumulate to Wedge the tool, an excessive torqueA mounted onbearing 28 by Patented Aug.v v27,v 1963 lCe 2 means of pivot pin 30. Theblock 31 connects to shaft 32 by set screw 33 and is rotatably mountedin the block 34, positioned underneath the platform 9. Lt is'connectedto the arm 315 by th clamp 36'.- f a t The cone 39, mounted onfthe shaft:5, is positioned between the cones 37 and 38 ofthe spoo1'14. 7

Shaft 35, carrying the chuck 35"l for the too1-38, is rotatably mountedin the table 9 andcarries a section of larger diameter 40, on which ismounted a key 41. The upper extension 42 of the shaft 36 .is threadedand carries a threaded disc 43, with a truncated,conical edge section43' and the lock nut 44.

The shaft 42 is rotatably connected to a lead screw`45 by the notch 46in the lead screw `45 and the pin 41 in the shaft 42. A split nut 47 isheldin position \by the bracket may Abe developed which may, rundercertain conditions,

snap the tool. Additionally, the advance of the tool, if dependent uponthe operators skill, is uncertain, sothat the aboveclass wherein therate of advance of the rotating tool may be preset. .v

These and 'furtherobiects of my invention will be understood by thoseskilled inthe art by reference to the drawings, of which: v f

FIG. 1 is a vertical side view of the tool of my invention;

FIG. 2 isa View `taken along line 2 2 of FIG. l;

VFIG. 3 is a detail W'ew, pantly in section, taken on line 3-3ofFIG. 1;

FIG. 4 is a section taken along 4-4 of FIG. 3;

FIG. 5 is a detail taken along S-5 of FIG. 4;

BIG. 6 is a detail taken along.i6;6 of lFIG. lg'and FiG. 7 shows adetail of amodiiioation of the tool of my invention. l

The base 1 carriesxthe standard 2 on Iwhich is adjustably mounted ablock `4, carrying the shaft 5 rotatably mounted in a bearing V'andcarrying the pulley 7 and belt 8, driven from any suitable power source.Mounted on the block 3 is the platform 9. Block 3 is connected by plate11 toblock 4. Plate 11 carries the plate .10 and platform 9. A top plate'10` ismounted on the side plates 11, carried on the base 41. Ashaftz12, journaled -in the bearing .13 positioned in the plate v10,carries the spool 14, adjustably positioned on the shaft |12 by means ofa set screw. Sleeve l19 also carries the sprocket 15 and plate 1 16 ofthe friction clutch 17 and 15. The complementary faces of clutch 15 aremounted one on the spool cone 38 and the other on the sleeve 19. Thefriction clutch face 16 is mounted on the sleeve 19, and thecomplementary face 18 on the sleeve 18. Rotation between the shaft 20andthe plate 18 is produced by means of the notch 21 in the sleeve 19and the pin 22 on the stub shaft 2.0. I The stub shaft 20 is threaded toreceive a nut 1:22. The spring 22 is positioned between the nut 122 andthe plate 1S. The extension 24 of the shaft 20 carries a collar 25 andextends through platform 9 in suitable bearings 2:6. The spring -27 isplaced on shaft 24 between the collar 25 and the platform '9. Theextension 27 of the shaft 24 is rotatably mounted on the bearing 28,positioned inthe block 3l (see FIGS. 3 and 4). Block 31 is pivotally 48,held on the plate 1li by the stud 49, between centering blocks 47'.

The sprocket 50 is mounted on the sleeve 51, which carries a keyway'SZ(see Vvl"[G.,6) and an external groove 53. The sleeve 50 is slidablymounted on fingers 54, mounted in the Wall 111. A sprocket chain drivesthe sprocket Sil from the sprocket 15. v

Fingers '55 and [56 are pivotally mounted on table9. They ride on theirarcuate bottoms 57 and 58, on the table 9, and are held on the table 9by means of bolts 60 andl 61 so as to permit them to rock on table 9(see FIGS. 4 and 5). (Finger `55 carries a notch 59 to engage the end ofthe tinger15 6t Finger '56 has an extension 62 to which is connected arod `63 which passes through the table9 and is connected to the block31.

With the shaft 5 stationary and the arm 35 undeected, the collar 25- andnut 22 are adjusted so that the weight of the assembly is balanced bythe spring 27 and the cone 39 is positioned centrally between the cones37 and 38. With the motor stationary and the arm 35 horizontal,

cone.39 contacts cone 37. Assume that the stroke limit' disc 43 ispositioned at position B. The arm 35 is depressed. This raises the shaft27, to contactthe cone 38 with the cone 39, and presses the plates ofthe frictionv y rotates the lead through y45 and the ynut, 47`and feedsthe shaft `42 downy through the sleeve 53. When `the tool has reachedthelirnit of its'lower. travel whichy isdesired for the tool, thearm 35is raised to its central position. This pulls the shaft 27, compressingthe spring so the weight of the assembly lrides on the spring 27 and thecone 39 is again centrally between the cones 37 and 38. This stops themachine and the tool movement. With the power off, the arm 35 is againdepressed, central cone 39 contacts cone 3S, and the stroke limit discis adjusted so that it makes rm contact with the cone 38 (see posi-"tion A).

. between the cone 37 the cone 39. This stops the 4 rotation of thespool `14 and prevents the nut 44 from hitting the lead screw 45.

As will be observed, clutch `17 may be omitted if desired. But since l15and 17 are slipping clutches, it provides a safety feature.

Provision is made to prevent the override of the tool,v

even if the setting of the disc 43 has not 4been made adeto force theshoulder '519' against the table 9, thus stalling the machine tool.

When S9' contacts the end of lingerrSiS, it will rock the fingercounterclockwise, which lifts the end of the dinger 56, interlockingwithY the step 59 of the linger 55. This depresses the extension 62 andthe rod 63,- which thus ro- Dates the arm 35 clocktwise and pulls theshaft7 downward, to. disengage cone 38 from cone 39.

FIG. 7 shows an alternative arrangement which may replace ther safetylatchlcomposed of fingers "'5 and 56 andthe associated mechanism. Thus,I may mount the conical disc 61? by means of a set screw 62 on the shaft42, 'underneath the disc `43. Disc "61'V has a conical edge 63 of thesameA slope as the cone 318 and fthe disc 43, and being of smallerdiameter, and it is set on the shaft 42 so thatit will Contact the cone38 just prior to the arrival of the shoulder '59 at the platform 9.Thus, if, for some reason, the cone y42 has been incorrectly set, thecone 63 will contact the cone 38 and depress the cone, to separate itfrom the cone 39 and stop the machine before the shoulder '59 hits thetable 9.

With the work set into place, the tool 38 set in position, and themachine adjusted, the arm 35 is depressed, contacting cones 38 and 39.'The tool is rotated and advanced at the rate determined by the pitch ofthe lead screw A45'and is independent of the pressure exerted on 35. Itwill also be observed that the axial force on the tool 38 is determinedby the pitch of the lead screw and the force exerted by the spring Z2'.rotation of the tool is excessive, slippage will occur at the clutchesy1 5 :and 17, and twist off at the tool 38 is pre- Vented.

When [the tool has advanced the distance determined by the setting ofthe disc 43, the disc contacts the cone 38, pulling it away from thecone 39, stopping the machine.

The tool 38 may be withdrawn by moving the arm 315 upward tol contactthe cones 39 and 37, as described above.

While I have described a particular embodiment of my invention forpurposes of illustration, it should be understood that variousmodifications and adaptations thereof may be made within `the spirit ofthe invention, as set forth in the appended claims.

I claim: f

1. A machine tool comprisin (l) a shaft and a power transmission spoolmounted on said shaft, y

(a) said spool including a pair of spaced cones; (2) apower transmissioncone rotatably mounted betweensaid cones referred to in (a) above, on anaxis perpendicular to the said shaft, and means to rotate tIf theresistance to` said power transmission cone from a power source; (3)means to rotatably mount said shaft and means to axially displace saidshaft; (4) a second shaft rotatably mounted adjacent to and along saidrst-named shaft;

(a) a power transmission means from said first named shaft to saidsecond shaft; (5) a lead screw connected to said second shaft, to

axially move said shaft during rotation;

(6) a stop disc mounted on said second shaft and extending betlween saidspaced cones on said spool; (7) and means yto mount la rotating cutting.tool at one end of said second shaft. 2. In the machine tool of claiml, said mea-ns referred to in (3) of claim l including bearings for saidshaft re# ferred to in l) of claim l, a spring support connectedto saidshaft, and means to axially displace said shaft through said bearings.

3. lIn the machine tool of claim 1, saidk shaft referred to in (l) ofclaim l comprising a pair of axially aligned shafts, one of said pair ofsaid shafts connected to said spool, the second of said shafts ofsaidpair of shafts connected to one end of a compression spring,theother end of said compression spring mounted on a support, and means totransmit rotation between said shafts, and means to :transmit axialdisplacement of said second shaft of said pair of shafts to the yfirstmentionedshaft of said pair of shafts. v

4. In the machine tool of claim 1, means -to adjustably mounted saidstop disc along said second shaft.

5. In the machine tool of claim l,

(l) a platform;l

(2) said iirst and said second f shafts referred to in claim l, `beingrotatably mounted in said platform; (3) a shoulder on said second `shaftbetween said stop disc and said platform, said means referred to in (2)of claim 1 to axially displace'said shaft in said bearing comprising A(4) a lever, a pivot for said lever mounted under said platform, abearing for said rstshaft referred to in `(1) of claim 1 mounted on saidlever, said shaft being rotatably mounted in said bearing; and

(5) a rocker arm mounted for rocking action on said platform, meansconnected t0 said rocker arm to move said bearing and lever referred toin (4) above on contact of said shoulder referred to in (3) above l withsaid rockerarm.

References Cited in the le of this patent UNITED STATES PATENTS

1. A MACHINE TOOL COMPRISING (1) A SHAFT AND A POWER TRANSMISSION SPOOLMOUNTED ON SAID SHAFT, (A) SAID SPOOL INCLUDING A PAIR OF SPACED CONES;(2) A POWER TRANSMISSION CONE ROTATABLY MOUNTED BETWEEN SAID CONESREFERRED TO IN (A) ABOVE, ON AN AXIS PERPENDICULAR TO THE SAID SHAFT,AND MEANS TO ROTATE SAID POWER TRANSMISSION CONE FROM A POWER SOURCE;(3) MEANS TO ROTATABLY MOUNT SAID SHAFT AND MEANS TO AXIALLY DISPLACESAID SHAFT; (4) A SECOND SHAFT ROTATABLY MOUNTED ADJACENT TO AND ALONGSAID FIRST-NAMED SHAFT;